Electric heater assembly

ABSTRACT

A flexible radiant heater assembly for radiantly heating a structure having a curved surface comprises a plurality of longitudinally flexible ribbon heaters juxtaposed in spaced parallel relationship. An upright piece extending upwardly at right angles to the plane of the ribbon heater is provided at each end of each heater. The heaters are electrically connected together in series by conductor wires joining the upright preces of adjacent heaters. A plurality of heat-proofing and insulating holder members extend transversely of said heaters at spaced points in the longitudinal direction thereof with each of the holder members being secured to a major face of each of the heaters. The major surface of each heater has an adiabatic fabric mounted thereon and the holder members hold the heater and fabric together by compression. The outermost ones of the holder members are secured to the upright pieces at the ends of the heaters. Legs secured at the opposite ends of each of the holder members depend vertically therefrom and extend beyond the other major surface of each of the heaters so as to hold the heaters in spaced relationship from the surface to be heated.

United States Patent 11 1 I Tanaka 1 1 ELECTRTC HEATER ASSEMBLY [76]inventor: Yukio Tanaka, 16-19 Shimouma 4-chome, Setagaya-ku, Tokyo,

Japan Y [22] Filed: Dec. 2, 1971 [21] Appl. No.: 203,998

219/531, 219/535', 21'9/549, 338/210, 338/319 51 1m.c1....' 1105b 3/0258 Field ofSearch ..219/339, 342, 350-358,

Hess I: 2191550 1 July 31, 1973 Primary ExaminerAnthony BartisAttorney-Nelson Littell et al.

[5 7 1 ABSTRACT A flexible radiant heater assembly for radiantly heatinga structure having a curved surface comprises a plurality oflongitudinally flexible ribbon heaters juxtaposed in spaced parallelrelationship. An upright piece extending upwardly at right angles totheplane of the rib H bon heater is provided'at each end of each heater.The

heaters are electrically connected together in series by conductor wiresjoining the upright preces of adjacent I heaters. A plurality ofheat-proofing and insulating holder members extend transversely of saidheaters at spaced points in the longitudinal direction thereof with eachof the holder members being secured to'a major face of each of theheaters. The major surface of each heater has an adiabatic fabricmounted thereon and the holder members hold the heater and fabrictogether by compression. The outermost ones of the holder members aresecured to the upright pieces at the ends of the heaters. Legs securedat the opposite ends of each of the holder members depend verticallytherefrom and extend beyond the other major surface of each of theheaters so as to hold the heaters in spaced relationship from thesurface to be heated.

2 Claims, 5 Drawing Figures 1 ELECTRIC HEATER ASSEMBLY BACKGROUND OF THEINVENTION This invention relates to a radiant electric heater assemblysuitably employed for radiantly heating a structure having a curvedsurface such as a ship hull, tubular body or the like. l

Large structures having curved surfaces employed in a various industrialfields are required to be heated. For example, in the ship buildingindustry, welded joints on ship hulls are required to be heattreated.According FIG. 2 is a cross-sectional view taken substantially along theline'2 2 of FIG. 1 and showing one heater and its associated parts ofthe assembly;

FIG. 3 is a cross-sectional view taken substantially along the line 3 3of FIG. 1 and showing another portion of the heater and its associatedparts of FIG. 2;

FIG. 4 is a view of an arrangement of a plurality of heater assemblieseach corresponding to that as shown to one of the conventionalmethodsfor heat-treating";

SUMMARY OF THE INVENTION I Therefore, one object of the presentinvention is to provide a radiantelectric heater assembly and apparatuswhich facilitates preparation for heating operation for a structurehaving a curved surface.

Another object of the present invention is to provide a heater assemblyand apparatus of the above. type which can be vers'atilelyappliedtostructures having varying sizes and curvatures to be heated.

in FIG. I which arrangement is for heating a structure having a largecurved surface; and A FIG. 5 is a view showing mechanical-and electricalconnections between adjacent heaterassemblies in said g arrangement ofFIG. 4. I

PREFERRED EMBODIMENT OF THE INVENTION The present invention will be nowdescribed referring to theaccompanying drawing and more particularly, toFIG. 1 thereof. In FIG. 1, one preferred embodiment of the heaterassembly of the invention is generally shown by reference numeral 1 andthe heater assembly generally comprises a plurality of longitudinallyflexible ribbon heaters 2 which are juxtaposed in such aspacedrelationship that the axes of these heaters extend parallel to eachother. Each 'of these heaters2 comprises a conventional electric heatingstrip which is essentially flexural or flexible in the longitudinaldirection and therefore, the strip is required to have a relativelysmall thickness such as 1 mm, for example. The heater or strip 2 has atthe opposite ends integral upright pieces 2a fonned by upwardly bendingthe strip'2 atthe oppo 5 site ends at rightfangles to oneof the majorsurfaces of the strip 2. The adjacent ribbon heaters 2 are electriAccording to the present invention, there has been provided an electricheater assembly for. radiantly heating a structure having a curvedsurface comprising a plurality of longitudinally flexible ribbon heatersjuxtaposed in parallel and spaced relationship; means for electricallyconnecting said heaters; an electric power supply for supplying electricpower to said heaters; heat-proofing and insulating holder membersextending transversely of said heaters at spaced points in thelongitudinal direction of each of the heaters on one major surface ofeach of the heaters, each of said holder members beingsecured to onemajor surface of each of the heaters; legs secured to said holdermembers depending vertically therefrom and extending beyond the othermajor surface of each of the heaters for'holding the heaters in spacedrelationship from the surface of the structureto be heated. l

The above and other objects and attendant advanrages of the present,invention will be more readily apparent to those skilled in the art fromareading of the followingdetailed description of the invention inconjunction with the'accompanying drawing inwhich onepreferredembodiment of the invention is shown for illustration purposeonly, but not for limiting the scope of the same in anyway.

BRIEF DESCRIPTIONOF THE DRAWING FIG. 1 is a perspective view of onepreferred embodiment of radiant electric heater assembly constructed inY accordance with the present invention with portions thereof brokenaway; I

cally connected at alternate one end upright piece'2a" of each heater bymeans of a conductor wire 3. The other end upright pieces 2a of theoutermost ribbon heaters 2 are provided with conductor wires 4 which areadapted to connect these outermost ribbon heaters to the correspondingribbon heaters of adjacent heater holder members 6 which are preferablyformed of the heat-resisting and thermally andelectrically insulatingmaterial sold under the trade name Hemmit Rod extend transversely of thejuxtaposed ribbon heaters 2 at spaced points in the longitudinaldirection of each of the heaters and pressed against the fabrics 5 underpressure sufficient to compress thefabrics 5 down. The

holder members 6 are secured to the he'aters2 by wires 7 in the mannerwhichpwill be described hereinbelow.

That is, each of the wires 7 associated with'the outer most holdermembers 6 extends along the inner side of the associated holder memberand then through transverse through holes 6a in the holder member toproject out of the outer side of the holder member andthe ex-' I alongthe underside of the associated heater 2 and then through vertical holes6b in the associated holder member to project out of the upper side ofthe holder member and the exposed opposite ends of the wire 7 are may beemployed inassociation with the outermost holder members 6 in the samemanner as mentioned in connection with the wires associated with therest of the holder members referred to hereinabove. It will beunderstood thatsince the holder members 6 are disposed at longitudinallyspaced points of each heater 2 and hold the same together, the heatersare assembled in such a manner that they are allowed to flex in thelongitudinal direction. The opposite ends of each of the holder members6 are shown as extending beyond the outer edges of the outermost heaters2.

In order to keep the ribbon heaters 2 spaced in a predeterminedrelationship from a curved surface of a structure to be heated,depending legs 8 are connected to the opposite ends of each of theholder members 6 in a conventional manner and the legs depend verti'cally and downwardly from the upper surface of the respectivelyassociated holder members and extend beyond the undersurfaces of theheaters-2. The legs 8 may be formed of a metal such as aluminum or anyother suitable heat-resisting and insulating material.

' Turning now to FIG. 4, there'is shown an arrangement comprising aplurality of ribbon heater assemblies juxtaposed and electricallyconnected each corresponding to that shown in FIG. 1 and the arrangementis suitable employed for-heating a structure having'a relatively largesize. However, it will be easily appreciated that if the structure is ofa relatively small size, only one heater assembly is sufficient to heatsuch a structure. In FIG. 4, the structure to the heated is shown byreference numberal 9 and the heater assemblies l are disposed alongthe-curved outer periphery of the structure with the axes of the ribbonheaters 2 in adjacent assemblies in alignment with each other and heldin position by any suitable conventional means. As describedhereinabove, with each heater assembly, since the holder members 6 arespaced in the longitudinal direction of the respectively associatedribbon heaters 2, the heaters and accordingly, the entire heaterassembly is allowed to flex in the longitudinal direction of its heaters2. Therefore, the heater assemblies can easily follow the curved contoursurface of the structure. As shown in FIG. 5, adjacent heater assembliesare conveniently connected to each other by means of connection means10. The connection ,means lis shown as comprising an arm 11 extendingbetween the legs 8 of the outermost holder members 6 in the adjacentheater assemblies and screws 12 which secure the arm to the adjacentlegs 8. For the purpose, as shown in FIG. 1, the legs 8 associated withthe outer- 4 associated with the outermost holder members 6 of theoutermost heater assembles l in the arrangement as shown in FIG. 4 areconnected to a power supply (not shown) To supply electric power to theheaters. Alternatively, the heater assemblies can be in parallelconnected to the power supply. Otherwise, the heater as semblies may beconveniently connected to a three phase power supply in a conventionalmanner. If an arrangement comprises 'a great number of heat assemblies,the assemblies may be grouped into aplurality of groups and theassemblies in each group may be inseries connected to each other and thegroups may be in parallelconnected to each other". When electric poweris allowed to flow through the heater assemblies in such amulti-arrangement, the heater assemblies can radiantly heat a curvedsurface of a structure to perform a desired treatment on the structure.

In order to prevent the holder members from displacing due to vibrativeforce which will develop when electric power is supplied to the heaterassembly or assemblies, the adjacent holder members can be additionallymaintained in a desired or predetermined spaced relationship by means ofmetal wires or the like.

While there has been described what is at present,

considered to be the preferred embodiment of this invention, it will beobvious to those skilled in the art that various changes andmodifications may be made therein without departing from the invention,and it is aimed, therefore, in the appended claims to cover all suchchanges and modifications as fall within the true spirit and scope ofthe'invention. What is claimed is:

l. A heater assembly for radiantly heating a structure having a curvedsurface, which comprises a plurality of longitudinal-1y flexible ribbonheaters juxtaposed inparallel and spaced relationship; means forelectrically connecting said ribbon heaters comprising an'upright pieceextending upwardly at rightangles 'to the plane of the heater and aconductor wire connecting said upright pieces at the corresponding oneend of'adjacent heaters; an electric power supply for supplying electricpower to said heaters; a plurality of heat-proofing and insulatingholder members extending transversely of said heaters at spaced pointsin the longitudinal direction of each of the heaters, each of saidholder members being secured to one major surface of each of theheaters; said major surface of each of the ribbon heatmost holdermembers 6 are preferably provided with v threaded holes for receivingthe screws 12. The conductor wires 4 of adjacent heater assemblies 1 areelectrically connected to each other in any conventional suitable manneras shown at 13. The conductor wires ers having an adiabatic fabricmounted thereon and' said holder members holding the heaters andtheirfabrics together so as to compress the fabrics down; the

outermost ones of said holder members being secured to said uprightpieces of the heaters; and legs secured to said holder members at theopposite ends of each of the holder members depending verticallytherefrom and extending beyond the'other major surface of each of theheaters so as to hold the heatersin spaced relaj tionship from thesurface of said structure.

2. An apparatus for radiantly heating a structure member having a curvedsurface which comprises a plurality of heater assemblies juxtaposed, andeach 1 heater assembly comprises a plurality of longitudinally extendingbeyond theiother'major surface of each of the heaters so as to hold theheaters in spaced relationship from the surface of said structure; meansfor mechanically connecting the legs associated with the outermostholder members of adjacent heater assemblies and said ribbon heaters ofeach assembly being electrically connected to an electric power supplyfor supplying electric power to the heaters. l

1. A heater assembly for radiantly heating a structure having a curved surface, which comprises a plurality of longitudinally flexible ribbon heaters juxtaposed in parallel and spaced relationship; means for electrically connecting said ribbon heaters comprising an upright piece extending upwardly at right angles to the plane of the heater and a conductor wire connecting said upright pieces at the corresponding one end of adjacent heaters; an electric power supply for supplying electric power to said heaters; a plurality of heat-proofing and insulating holder members extending transversely of said heaters at spaced points in the longitudinal direction of each of the heaters, each of said holder members being secured to one major surface of each of the heaters; said major surface of each of the ribbon heaters having an adiabatic fabric mounted thereon and said holder members holding the heaters and their fabrics together so as to compress the fabrics down; the outermost ones of said holder members being secured to said upright pieces of the heaters; and legs secured to said holder members at the opposite ends of each of the holder members depending vertically therefrom and extending beyond the other major surface of each of the heaters so as to hold the heaters in spaced relationship from the surface of said structure.
 2. An apparatus for radiantly heating a structure member having a curved surface which comprises a plurality of heater assemblies juxtaposed, and each heater assembly comprises a plurality of longitudinally flexible ribbon heaters juxtaposed in parallel and spaced relationship; means for electrically connecting said heaters comprising an upright piece formed by upwardly bending each of the heaters at the opposite ends of the associated heater at right angles to the plane of the heater and a conductor wire connecting said upright pieces at the corresponding one end of adjacent heaters; a plurality of heat-proofing and insulating holder members extending transversely of said heaters at spaced points in the longitudinal direction of each of the heaters, each of said holder members being secured to one major surface of each of the heaters and the outermost ones of said holder members being secured to said uprIght pieces of the heaters; and legs secured to said holder members at the opposite ends of each of the holder members depending vertically therefrom and extending beyond the other major surface of each of the heaters so as to hold the heaters in spaced relationship from the surface of said structure; means for mechanically connecting the legs associated with the outermost holder members of adjacent heater assemblies and said ribbon heaters of each assembly being electrically connected to an electric power supply for supplying electric power to the heaters. 